• Journal of Environmental Science International
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• v.31 no.8
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• pp.677-689
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• 2022

In order to photocatalytically treat organic matter (COD_Cr) and chromaticity effectively, chemical coagulation and sedimentation processes were employed as a pretreatment of the leachate produced from landfill in Jeju Island. This was performed using FeCl₃·6H₂O as a coagulant. For the treated leachate, UV/TiO₂ and UV/TiO₂/H₂O₂ systems were investigated, using 4 types of UV lamps, including an ozone lamp (24 W), TiO₂ as a photocatalyst, and/or H₂O₂ as an initiator or inhibitor for photocatalytic degradation. In the chemical coagulation and sedimentation process using FeCl₃·6H₂O, optimum removal was achieved with an initial pH of 6, and a coagulant dosage of 2.0 g/L, culminating in the removal of 40% COD_Cr and 81% chromaticity. For the UV/TiO₂ system utilizing an ozone lamp and 3 g/L of TiO₂, the optimum condition was obtained at pH 5. However, the treated COD_Cr and chromaticity did not meet the emission standards (COD_Cr: 400 mg/L, chromaticity: 200 degrees) in a clean area. However, for a UV/TiO₂/H₂O₂ system using 1.54 g/L of H₂O₂ in addition to the above optimum UV/TiO₂ system, the results were 395 mg/L and 160 degrees, respectively, which were within the emission standard limits. The effect of the UV lamp on the removal of COD_Cr, and chromaticity of the leachate decreased in the order of ozone (24 W) lamp > 254 nm (24 W) lamp > ozone (14 W) lamp > 254 nm (14 W) lamp. Only COD_Cr and chromaticity treated with the ozone (24 W) lamp met the emission standards.

• Journal of Bio-Environment Control
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• v.31 no.1
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• pp.8-13
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• 2022

This study was carried out to investigate the proper wattage and installation distance for the efficient use of nano-carbon fiber infrared heating lamp (NCFIHL), a heating device advantageous for heating energy saving, when the production of watermelon plug seedlings in the plug seedling nursery in winter season. Six small beds were divided into plastic film, and 700 W and 900 W nano-carbon fiber infrared heating lamps were installed at 100 cm above the bed. 1 lamp at central (control), 60 cm interval (2 lamps), and 40 cm interval (3 lamps) heating lamps were installed in each bed inside the greenhouse. All treatments, except the control, were set to keep the night air temperature at 20℃ after lighting the NCFIHL. The leaf temperature showed a tendency to increase fast as the install distance was narrow. The leaf length and leaf width tended to increase as the installation distance of the 700 W heating lamp was narrow. The compactness was high in 700 W heating lamp with 40 cm of installation distance. Therefore, in consideration of maintaining the set temperature at night, installing 700 W electric lamps at 40 cm was an efficient power and installation distance for watermelon grafted seedlings considering economic feasibility.

• Journal of Environmental Policy
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• v.14 no.1
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• pp.135-158
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• 2015

An efficient management system of mercury-containing waste was designed by reviewing the management and treatment of spent fluorescent lamp in Korea and foreign countries. According to Waste Management Act in Korea, mercury-containing wastes from households are classified as municipal solid wastes even though mercury-containing wastes pose hazardous risks. In general, hence, mercury-containing wastes from households are not being managed properly because those wastes from households were not classified as specific wastes (or hazardous wastes). Some mercury-containing wastes are managed as a mandatory target item in waste charge system and Extended Producer Responsibility (EPR) system under Act on Promotion for Saving and Recycling of Resources. An efficient management plan of mercury-containing wastes can be derived with an improved collection system, designating disposal sites and advanced treatment facilities for spent fluorescent lamps. Finally, the role of each agent involved from collection to disposal of mercury-containing wastes was suggested to establish the efficient management system for mercury-containing waste.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.4
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• pp.756-762
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• 2009

This paper proposes a high efficient Dual Buck Inverter design with a zero voltage switching (ZVS) control technique. The ZVS control is realized by adding a feedback loop circuit which is implemented by simple RS latch and TTL gate. The used load was 200W -Ceramic Metal Halide Lamp. The experimental results show that the proposed Inverter system could avoid the acoustic resonance and achieve high efficiency by Zero Voltage Switching.

• Proceedings of the KIEE Conference
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• 2007.10c
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• pp.157-159
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• 2007

For a vessel to safely navigate on the ocean, it is required to check the vessel position as frequently as possible. When a vessel navigates oil the ocean or entering/leaving a port, the target area such as islands, points and mountain peak, etc. are used. However, when such target are not available or when vessel navigates in night time, installed artificial navigation aid facilities help successful vessel navigation. Light Wave Aid helps to confirm a position to the navigator directly and quickly. So, the synchronous light to display the accurate signal has wide applications. However, lantern domestic industry is small, and most of the products show non-compatibility. Consequently, this paper presents the synchronous lighting using UTC of GPS, which maintains compatibility with different lanterns. Also, by replacing conventional electric bulb with LED lamp, simple and efficient lighting system is obtained.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.11
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• pp.508-511
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• 2003

In this paper, electrical characteristics of inductively coupled plasma in an electrodeless fluorescent lamp were investigated using a Langmuir probe with a variation of argon gas pressure. The RF output was applied in the range of 5 ∼ 50 (W) at 13.56 (MHz). The internal plasma voltage of the chamber and the probe current were measured while varying the supply voltage to the Langmuir probe in the range of -100 (V) ∼+100 (V). When the pressure of argon gas was increased, electric current was decreased. There was a significant electric current increase from l0W to 30 〔W〕. Also, when the RF power was increased, electron density was increase. This implies that this method can be used to find an optimal RF rower for efficient light illumination in an electrodeless fluorescent lamp.

• Journal of Electrochemical Science and Technology
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• v.3 no.1
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• pp.44-49
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• 2012

Electrochemical and photochemical techniques have been proved to be effective for the removal of organic pollutants in textile wastewater. The present study deals with degradation of synthetic textile effluents containing reactive dyes and assisting chemicals, using electro oxidation and photo catalytic treatment. The influence of various operating parameters such as dye concentration, current density, supporting electrolyte concentration and lamp intensity on TOC removal has been determined. From the present investigation it has been observed that nearly 70% of TOC removal has been recorded for electrooxidation treatment with current density 5 mA/$dm^2$, supporting electrolyte concentration of 3 g/L and in photocatalytic treatment with 250 V as optimum lamp intensity nearly 67% of TOC removal was observed. The result indicates that electro oxidation treatment is more efficient than photocatalytic treatment for dye degradation.

• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.126-132
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• 2005

UV disinfection system allows the disinfection of municipal and industrial water and wastewater without the use of expensive chlorination and dechlorination techniques, labor intensive equipments In traditional ultraviolet systems the UV lamps are seperated from water by quartz sleeves. quartz is one of. the few materials that is virtually transparent to UV light, the UV lamp is placed inside the Quartz sleeve. UV light from the lamp is passed through the quartz and into the water, thereby providing disinfection. In fluoropolymer tube-used non-contact UV systems, the water flows through fluoropolymer plastic tubes. banks of UV lamps surround these tubes such that each tube gets exposed to ultra violet light from all sides. in non-contact design the lamps operates at almost constant temperature. this design is extremly efficient in the utilization of UV energy and superior to conventional contact- systems.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.14 no.2
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• pp.78-84
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• 2000

마이크로파 방전 무전극 황전등은 마그네트론에서 발생된 마이크로파로 이원자 황을 여기하여 방출되는 빛을 조명에 사용하는 차세대 조명기구이다. 이원자 황에서 방출된 빛은 자외선과 적외선이 매우 적고 가시광선 영역에서 연속적인 분광 분포를 가지며 발광 효율은 100[1m/W] 이상으로 매우 높다 본 논문에서는 전력연구원에서 국내 최초로 개발한 마이크로파 여기형 무전극 방전등을 소개한다. 방전구의 회전, 방전전력과 압력의 조정, 및 Na 등의 첨가를 통해 전등의 상관색온도를 가변(2,500 - 10,000 K 범위)하였다. 아울러 연색성 평가수를 90 이상으로 개선 할 수 있음을 보였다.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.4
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• pp.108-112
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• 2017

High-intensity-discharge lamps are widely utilized in outdoor and indoor lighting circumstances that need high luminance. In lighting applications for MHD lamps, the size of the lamp ballast circuit is an important factor and should be as small as possible. The electronic ballast for MHD lamps is superior to the electromagnetic(EM) ballast in that it saves energy, and has smaller volume and lighter weight. In this paper, highly efficient cost-effective and small sized electronic ballast for Metal Halide Lamp with high power factor using Digital Signal Processor are proposed. The proposed electronic ballast for MHD lamps combines a boost PFC converter with a half-bridge inverter, the algorithms of the power factor correction and ballast control were implemented using the TI's TMS320LF2406 CPU. Experimental results validate the ballast is also useful and reasonably suggested.